1. Field of the Invention
This invention relates generally to surgical instrumentation and, more specifically, to distractor and compressor instruments.
2. Background Information
Various medical instruments and appliances are used in the treatment of spinal column deformities and injuries. In certain medical circumstances, it is necessary to place is a mechanical device, such as a stabilization rod, adjacent to the spine. This is to promote the natural healing of the spine in a straight spatial disposition, or to enhance straightening of the spine in cases of disease such as scoliosis. In some surgical procedures, chips of bone which have been removed from another portion of the body, such as the hip, are placed in proximity to the healing spinal site. These chips act as mortar to promote bone fusion.
The spinal rods are placed along the spinal column and various fixation appliances are mounted along the rods to maintain the rods in the desired position and orientation. Implants are pushed up and down the rods such as hooks. Rod holders may be used as a stop. While a surgeon is mounting the rods, rod hooks and various other components, the surgeon pushes items along the rod and may either distract bone by pulling it away from the work site or must compress bone to pull it together if broken, for example. A standard distractor/compressor is used to accomplish these and many other actions during spinal surgery.
In certain procedures, the surgeon approaches the spinal column of the patient from an anterior position (the stomach area). Pressure is thus applied from some distance in order to move implants along a rod or to distract or compress a rod in place or to distract bone or implants into the most favorable position. The positioning is important in order to fix the correct position of the rods and the implants while providing the surgeon the best visualization of the work site.
Prior instruments required the surgeon or a member of the surgical team to hold a distractor directly at the desired angle, however, the distractor instrument itself may, in is such a case obstruct the surgeon""s view of the work site. It has been know to provide an instrument with a bend in it, to allow a better view, but the bend may not allow the most leverage when a good deal of force is required. Detachable tips have also been used, which detachable tips are placed on the end of a standard distractor allowing distraction or compression at a particular angle which allows the instrument to be rotated out of the surgeon""s view yet still applying pressure at the correct position on the rod or bone. However, these detachable tips require either a selection of the appropriate instrument prior to surgery, or may require changing the tips during surgery should the appropriate detachable tip not have been chosen. Additional detachable tips can be expensive and may lead to duplicative instrumentation. Changing tips can cause usage of time and efforts during surgical procedures.
This invention is an instrument for bone distraction and compression which has been fitted with ratcheting tips which are rotatably mounted at the working end of a bone distractor. The ratcheting tips are mounted such that they are adjustable to customize the instrument for a particular surgical procedure. The tips may be used to push implants along a rod. In that application, the tips include U-shaped ends that slide around the rod hooks or other components to urge the component into the position desired by the surgeon. The ratcheting tips, in accordance with one aspect of the invention, are adjustable at 15xc2x0 interval positions around a central axis to a maximum of about 90xc2x0. It is preferred to provide a ratcheted tip to avoid motion during surgery. The ratcheted tip allows the surgeon to adjust the angle to allow the best visualization, while maintaining the instrument in a plane that allows the optimum force to be applied.